Vaporproof building construction



Aug. l2, 1952 G. s. wlLLEY VAPOR-PROOF BUILDING CONSTRUCTION Filed Oct. 4, 1945 Imi/4 Patented Aug. 12, 1952 vAPonPnooF BUILDING coNsrrRUcTioN Grant S. Willey, Chicago, Ill., assignor v to United States Gypsum Company, Chicago, Ill., a, corporation of Illinois Application october 4, 1945, serai No. s2o,21s.

(Cl. 7,2-124i 7 Claims. 1-

VThe present invention relates to a vaporproof building construction.

More particularly thev invention concerns a type of vapor-proof building Construction comprising a foraminous' plaster-support that is ailixed to supporting structures such as studs and the like, and is provided with openings through which thereto applied plaster may pass for the formation of v.plaster keys behind the support, but which structure is provided'with means to prevent the transfer of humidity `from the space denedby they plaster Wall into the hollow wall space behind it.

With the advent of air-conditioning in modern homes and also the use vof insulation,v new problems have arisen which have tested the ingenuity of building constructors. One of these difficulties lies in thefact that there exists a very abrupt temperature gradient between the exterior of a house and the interior surface of the walls of the rooms thereof; this being occasioned by the fact that insulation is frequently used, or at least the air space between the wall of the room andthe outside wall of the house is depended upon to guard against both loss of heat in the wintertime and the absorption of heat by the rooms as a result of the high outside temperatures. y l

The diiliculty in therwinter is accentuated b the fact that it has now become quite common practice to humidiiy the rooms of a house, this being usually accomplished by humidifying devices associated with the heating system.

It is a well known fact that the ordinary plaster wall is pervious to moisture in the form of water vapor.` Moreover, the temperature on the inside of a room is generally kept on the order of between '70 and 75 F., while the outside temperature surrounding the house may be as low as to 20 below zero F. Naturally there Will exist in the space between the outer wall of the house and the wall of the room a temperature gradient between these two extremes of temperature. Inasmuch as cold air is capable of holding a great deal less moisture, it will follow that any moisture which penetrates through the plaster walls will be condensed within the space between the outer walls of the house and the walls of the room either in the form of water or, if the temperature is low enough, in the form of ice. When ice is formed, the conditions become greatly aggravated, as a considerable thickness of icev can build up which, as the temperature rises, will melt and therefore will turn into water, which not only will tend to run down the interiorof the walls and possi- 2 bly appear on the ceilings of the floor below, but also will tend to rot the timbers, studs, and beams of the house.

The most radical cure for this condition is to eliminate the humidication. This, however, makes the interior of the house very dry, and the average householder who is not aware of the formation of the ice or moisture in his walls usually tries to keep his home at about 30 per cent relative humidity. It is therefore-advisable to prevent the transmission of moisture into the space between the walls bythe use of a vaporimpermeablev barrier, and also thoroughly to ventilate ythe space beyond the vapor-prooi barrier, so that if any moisture should penetrate, nevertheless it` would be carried off. This can readily be 4done -in attics and mansards, but is not soeasy in the vertical walls of a building.

Therefore, the best Asolution'is simply to prevent `an impervious sheet of either asphalted or similarly waterprooiedI paper `and/or a sheet of metal foil, as for instancel aluminum foil.V The aluminum `foil is particularly advantageous in that itr not only provides I a thorough vapor-proof barrier, but also by reason `of its heat-reflecting properties prevents the" entry into the room of radiant heat, and also by reason of its low heatemissivity prevents the "radiation of heat from the room when the room.l is at a higher temperature than that of the lcircumambient atmosphere.

Such plasterboard, however, while excellent for producing walls, does not furnish quite as good Va plaster key as is desired. Moreover, in some parts'of the United States the building codes require the use of plaster-supports having means thereon or therein for the formation of plasterl keys. When plasterboard is used which does not have a vapor barrier on one side, this is usually accomplished by perforating the board, and manyv patents have been taken out on various types of perforated plasterboard, as for example perforated gypsum plasterboard as exempliiied by Roos Patent No. 1,938,354. Y

It will be self-evident, however, that merely to cover'the imperforate portions of the reverse side ci the-plasterboard with metal foil or other vaporbarrier wonld'n'ot` solve the problem above outlined,V because the plaster which extends through the perforations and forms clinching heads (so-called lkeys): would still'permit 4the passage of moisture through the said keys, and hence into the space between the outer and inner walls of the building.

Applicant has succeeded in solving this problem by providing a foraminous plaster support i which may, for example, be exemplified by a perforated gypsum plasterboard, wood-fiber board, asbestos insulation board, or similar plasteraccepting base, this being provided with a vaporimpermeabile backing membrane coextensive therewith, there also being provided extensible portions either associated with said membrane by attachment thereto or integrally formed therewith, these extensible portions permitting the intrusion thereinto of plaster keys which extend through the openings in the plaster support but which do not impair the continuity and vaporstopping characteristics of the backing membrane.

This may be accomplished in a number of specic ways all of which will be more completely hereinafter described in connection with a single sheet of drawings in which Fig. 1 is a perspective view, partly broken away and partly in section, of a wall construction embodying one of the preferred ways of accomplishing the results intended to be accomplished by the present invention;

Fig. 2 is a cross section, on an enlarged scale, of the construction shown in Fig. 1, the view being taken along the lines 2-2 of Fig. 1;

Fig. 3 is a cross section of a portion of a plasterboard having a vapor-impermeable backing membrane and extensible portions thereon;

Fig. 4 is a rear view of the one type of construction showing a plasterboard having extensible pockets subtending each of the openings or perforations in the plasterboard;

Fig. 5 is a cross section along the line 5-5 of Fig. 4, indicating the general appearance of a nished construction showing the distortion of the plaster key receiving pockets of the type shown in Fig. 5;

Fig. 6 is a side elevational view of one of the pockets shown in Fig. 4;

Fig. '7 is a cross sectional view of a portion of a wall showing both the outer and inner walls, but in a modied form, showing two plaster boards, one perforate and the other imperforate, the vapor-proof barrier being applied to the imperforate board; and

Fig. 8 is a perspective view, partially in section, of still another modification, in which the impermeable membrane is in the form of a readily distortable, for example crinkly, material.

IIlhe vapor barrier whichis provided may consist of a suitable vapor-impermeable material such for example as asphalt-saturated paper, paper or other fabric saturated or impregnated with an artiiicial resin preferably of a flexible type, as for example a vinyl resin or other elastomer; or a sheet of metal foil, for example, aluminum foil or tin foil, which may be used either alone or in the form of a metal foil-paper or fabric laminate. Ihe pockets may be merely folded portions oi this membrane or film, or they may be in the nature of a bellows having accordion pia-ited side walls. In other words, the exact nature of the material of which the membrane is made is subject to a wide choice and the invention is not limited, in its broadest sense. to any particular material, although a vapor-proof paper, a metal foil, or a metal foil-paper or fabric laminate 'are the three selected species which illustrate the general principles of the present invention.

Referring to Figs. 1, 2 and 3, these show a construction in which a foraminous plaster-support, for instance a suitable plasterboard I0, which is provided with suitable openings or perforations II and the usual cover sheets- I2 and I3, is also provided with a therewith coextensive backing sheet I4 which may for example be made of any of the materials hereinabove mentioned. This sheet while it may be, if desired, adhesively secured to the cover sheet I3 of the plasterboard, is provided with -longitudinally extending pockets I5 which are'so oriented that they will subtend an entire rQW of the openings II through which the plaster, keys penetrate.

As can best be seen from Figs. 1v and 2, which show the completed construction, there exists in the order named, and counting from the interior of the room, the plaster layer I6, the outer cover sheet I2 of the plasterboard, the core of the plasterboard, the inner cover sheet I3 of the plasterboard, the vapor-irnpermeable layer I4, and the pockets I5 formed therein. The plaster keys I1 protrude into the pockets I5 as can be clearly seen in Figs. 1 and 2. The plasterboards themselves are supported by studs I8, there being shown, for the sake of completeness, also the outer sheathing I9 and the theretoaixed clapboards 20. y

In the particular construction shown in Fig. 1, the pockets I5 extend the full length of each of the boards, even at those points wherethere are no perforations. The board when sold to the consumer will have the appearance in cross section as shown in Fig. 3, so that it can readily be put up in bundles because when shipped the pockets I5 are practically crushed at as shown in Fig. 3. When in use, however, the pockets are of course expanded as illustrated in Figs. 1 and 2. The pockets are crushed ldown flat against the studding in order effectively to seal the room from the wall-space behind the vapor barrier.

An alternative construction comprises applying a lcontinuous sheet I4 to the unperforated areas on the back of the board, and then to apply at such points as to surround the subtending openings II, a suitable telescoping type of pocket -25 (see Figs. 4, 5 and 6). These pockets are adhesively secured to the sheet I4 and when not in use are of course crushed iiat against the back of the board, which is possible by reason of the accordion plaits 26 which characterize this type of pocket. l

The means for securing the pockets 25 to the impermeable sheet may be some suitable water resistant adhesive, as for example asphalt and the like. When in use, the keys I1 Will cause the expansion of the plaits 26 and the general appearance of the pockets will be about as illustrated in Fig. 5. It is, however, within the contemplation of the invention to form these individual pockets 25 integrally with the sheet.

In Fig.' 8 there is illustrated another manner of accomplishing the purposes of the present invention in which case the sheet I4 is made of a crinkled fabric or metalfoil, or fabric or papermetal foil laminate. `This will be adhesively secured in certain' areas only to the plasterboard cover sheet I3 so that the sheet will still be suiiiciently extensible at those points which subtend the openings I0, so that when the plaster keys I'I are formed, they will push back the crinkled material to form the bulges or pockets 35 which are shown both in perspective as Well as in vcross section in Fig, 8. This construction is particu- 5. larly advantageous in that it is inexpensive and also is comparatively strong, as there is not much danger of tearing the pockets open during shipping of, the boards and the erection :of th structure. v

By the hereinafter used term extensible portions associated with said membrane it is intended to cover both the* type of elongated pockets shown in Figs. 1, 2 and 3, the accordion plaited pockets 25 shown in Figs. 4f and 5, and the selfformed pockets 35 formed in the crinkled sheet shown in Fig. 8.

There is still another manner of effecting the purpose of the present invention, this being illustrated in Fig. 7. In this case the plasterboard II) provided with the outer cover sheet I2 and the back cover sheet I3 is spaced from a solid plasterboard 30 which itself has cover sheets 3l and 32, but which is also provided with a continuous vapor impermeable barrier 34. A suitable furring means 36, which for instance may be in the form of slats, serves to afx the plasterboards 30 and Il! to each other, thus leaving a space 31 therebetween into which the plaster keys I1 may extend. The space 3l bounded by the plasterboards lil and 30 and the furring means or slats 36 thus serves as pockets for the reception of the plaster keys Il. It will be self-evident that the impervious sheet 34 might just as well be so oriented as to face toward the studs I8 and still accomplish the purpose of preventing access of moisture into the space between the outer sheathing I9 and the plasterboard 30.

While plasterboards have been shown as the preferred form of the present invention, it will be self-evident that the support could consist of a suitably perforated metal or other material, for instance it might be a type of plaster-support consisting entirely of comminuted wood liber, or in fact any type of perforated board to which plaster will readily adhere. In other words, the presence of the gypsum core within the plasterboard is not a limiting feature, but the invention has been described in connection -with the common type of plasterboard or wallboard because this is the preferred embodiment of the present invention.

Accordingly, and saving for himself such equivalents as will occur to those skilled in the art into which this invention falls, applicant claims:

1. A vapor-proof building element comprising a plaster support having a plurality of spaced plaster-receiving openings, and a substantially vapor-impermeable backing membrane secured in flatwise relationship to one surface of said support extending across said openings, said backing membrane being crinkled in those areas over said openings whereby to provide extensible plasterreceiving pockets when plaster is forced through said openings from the other surface of said support.

2. A vapor-proof building element comprising a wallboard having a plurality of spaced plasterreceiving openings therein, and a, substantially vapor-impermeable backing membrane adhesively secured in flatwise relationship to one surface of said wallboard extending across said openings, said backing membrane being crinkled over the openings thus providing extensible plaster-receiving pockets when plaster is forced through said openings from the other surface of said wallboard.

3. A vapor-proof building element comprising a plaster support having a plurality of spaced openings, and a substantially vapor-impermeable backing membrane secured in fiatwise relationship to one surface afraid-support and having portions extending over the openings and extensible outwardly'` therefrom, said portions each formed on opposite sides with a. `freely folded overlap of the membrane' extending from parts of the membrane secured to the support o n opposite sides of each opening', said portions being extensible to provide pocketsor mortarfforced through saidv openings frorn/ the. opposite` surface of the support. U Y.

4. A vapor-proof building `.element comprising a wallboard having a plurality of spaced plasterreceiving openings, and a substantially vaporimpermeable. backing membrane secured in flatwise relationship to one surface of said wallboard and having portions extending over the openings and extensible outwardly therefrom, said portions each formed on opposite sides with a freely folded overlap of the membrane extending from parts of the membrane secured to the support on opposite sides of each opening, said portions being extensible to provide pockets for mortar forced through said openings from the opposite surface of the wallboard.

5. A vapor-proof building element comprising a plaster support having a plurality of spaced openings extending therethrough and arranged in spaced rows, and a substantially vapor-impermeable backing membrane secured in flatwise relationship to one surface of said support between said rows but unsecured in the areas along said rows and having portions extending over the openings and extensible outwardly therefrom, said portions each formed on opposite sides with a freely folded overlap of the membrane extending from parts of the membrane secured to the support on opposite sides of each opening, said portions being extensible to provide pockets for mortar forced through said openings from the opposite surface of the support.

6. A vapor-proof building element comprising a wallboard having a plurality of spaced plasterreceiving openings extending therethrough and arranged in substantially parallel spaced rows, and a substantially vapor-permeable backing membrane adhesively secured in flatwise relationship to one surface of said support between said rows but unsecured in the areas along said rows and having portions extending over the openings and extensible outwardly therefrom, said portions each formed on opposite sides with a freely folded overlap of the membrane extending from parts of the membrane secured to the support on opposite sides of each opening, said portions being extensible to provide pockets for mortar forced through said openings from the opposite surface of the wallboard.

7. A vapor-proof building element comprising a wallboard, a substantially vapor-impermeable backing membrane secured in flatwise relationship to one surface of said wallboard, said element having a plurality of spaced plaster-receiving apertures extending therethrough and through said membrane, and a plurality of nat plaited and extensible substantially vapor-impermeable pockets adhesively secured to said backing membrane in the areas thereof encompassing said openings and extending with their open ends thereacross whereby to provide extensible pockets for mortar forced through said openings from the opposite surface of said wallboard.

GRANT S. WILLEY.

(References on following page) 7' n vIwlmENCES CITED UNITED STATES PATENTS Number 6 1 `Name Date White Nov. 3,1914 Lnkletter Nov. 7, 1916 Madison May 6, 1919 Cumfer Mar. 4, 1924 10 Number Name f Date Cohen July 10, 1928 Shedrck Mar. 8, 1932 Roos Dec. 5, 1933 Weyerhaeuser et a1. Feb. 11, 1936 Maier June 23, 1936 Thomas July 14, 1936 Herbest, Jr Dec. 13, 1938 Rowe June 4, 1940 Buttress Oct. 29, 1940 

